1 /*
2 * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/heapRegionRemSet.hpp"
27 #include "gc_implementation/g1/heapRegionSet.inline.hpp"
28
29 uint FreeRegionList::_unrealistically_long_length = 0;
30
31 //////////////////// HeapRegionSetBase ////////////////////
32
33 void HeapRegionSetBase::fill_in_ext_msg(hrs_ext_msg* msg, const char* message) {
34 msg->append("[%s] %s ln: %u cy: "SIZE_FORMAT,
35 name(), message, length(), total_capacity_bytes());
36 fill_in_ext_msg_extra(msg);
37 }
38
39 #ifndef PRODUCT
40 void HeapRegionSetBase::verify_region(HeapRegion* hr) {
41 assert(hr->containing_set() == this, err_msg("Inconsistent containing set for %u", hr->hrs_index()));
42 assert(!hr->is_young(), err_msg("Adding young region %u", hr->hrs_index())); // currently we don't use these sets for young regions
43 assert(hr->isHumongous() == regions_humongous(), err_msg("Wrong humongous state for region %u and set %s", hr->hrs_index(), name()));
44 assert(hr->is_empty() == regions_empty(), err_msg("Wrong empty state for region %u and set %s", hr->hrs_index(), name()));
45 assert(hr->rem_set()->verify_ready_for_par_iteration(), err_msg("Wrong iteration state %u", hr->hrs_index()));
46 }
47 #endif
48
49 void HeapRegionSetBase::verify() {
50 // It's important that we also observe the MT safety protocol even
51 // for the verification calls. If we do verification without the
52 // appropriate locks and the set changes underneath our feet
53 // verification might fail and send us on a wild goose chase.
54 check_mt_safety();
55
56 guarantee(( is_empty() && length() == 0 && total_capacity_bytes() == 0) ||
57 (!is_empty() && length() >= 0 && total_capacity_bytes() >= 0),
58 hrs_ext_msg(this, "invariant"));
59 }
60
61 void HeapRegionSetBase::verify_start() {
62 // See comment in verify() about MT safety and verification.
63 check_mt_safety();
64 assert(!_verify_in_progress,
65 hrs_ext_msg(this, "verification should not be in progress"));
66
67 // Do the basic verification first before we do the checks over the regions.
68 HeapRegionSetBase::verify();
69
70 _verify_in_progress = true;
71 }
72
73 void HeapRegionSetBase::verify_end() {
74 // See comment in verify() about MT safety and verification.
75 check_mt_safety();
76 assert(_verify_in_progress,
77 hrs_ext_msg(this, "verification should be in progress"));
78
79 _verify_in_progress = false;
80 }
81
82 void HeapRegionSetBase::print_on(outputStream* out, bool print_contents) {
83 out->cr();
84 out->print_cr("Set: %s ("PTR_FORMAT")", name(), this);
85 out->print_cr(" Region Assumptions");
86 out->print_cr(" humongous : %s", BOOL_TO_STR(regions_humongous()));
87 out->print_cr(" empty : %s", BOOL_TO_STR(regions_empty()));
88 out->print_cr(" Attributes");
89 out->print_cr(" length : %14u", length());
90 out->print_cr(" total capacity : "SIZE_FORMAT_W(14)" bytes",
91 total_capacity_bytes());
92 }
93
94 HeapRegionSetBase::HeapRegionSetBase(const char* name, bool humongous, bool empty, bool linked, HRSMtSafeChecker* mt_safety_checker)
95 : _name(name), _verify_in_progress(false),
96 _is_humongous(humongous), _is_empty(empty), _is_linked(linked), _mt_safety_checker(mt_safety_checker),
97 _count()
98 { }
99
100 //////////////////// HeapRegionSet ////////////////////
101
102 void FreeRegionList::set_unrealistically_long_length(uint len) {
103 guarantee(_unrealistically_long_length == 0, "should only be set once");
104 _unrealistically_long_length = len;
105 }
106
107 void FreeRegionList::fill_in_ext_msg_extra(hrs_ext_msg* msg) {
108 msg->append(" hd: "PTR_FORMAT" tl: "PTR_FORMAT, head(), tail());
109 }
110
111 void FreeRegionList::add_as_head(FreeRegionList* from_list) {
112 check_mt_safety();
113 from_list->check_mt_safety();
114
115 verify_optional();
116 from_list->verify_optional();
117
118 if (from_list->is_empty()) return;
119
120 #ifdef ASSERT
121 FreeRegionListIterator iter(from_list);
122 while (iter.more_available()) {
123 HeapRegion* hr = iter.get_next();
124 // In set_containing_set() we check that we either set the value
125 // from NULL to non-NULL or vice versa to catch bugs. So, we have
126 // to NULL it first before setting it to the value.
127 hr->set_containing_set(NULL);
128 hr->set_containing_set(this);
129 }
130 #endif // ASSERT
131
132 if (_head != NULL) {
133 assert(length() > 0 && _tail != NULL, hrs_ext_msg(this, "invariant"));
134 from_list->_tail->set_next(_head);
135 } else {
136 assert(length() == 0 && _tail == NULL, hrs_ext_msg(this, "invariant"));
137 _tail = from_list->_tail;
138 }
139 _head = from_list->_head;
140
141 _count.increment(from_list->length(), from_list->total_capacity_bytes());
142 from_list->clear();
143
144 verify_optional();
145 from_list->verify_optional();
146 }
147
148 void FreeRegionList::add_as_tail(FreeRegionList* from_list) {
149 check_mt_safety();
150 from_list->check_mt_safety();
151
152 verify_optional();
153 from_list->verify_optional();
154
155 if (from_list->is_empty()) return;
156
157 #ifdef ASSERT
158 FreeRegionListIterator iter(from_list);
159 while (iter.more_available()) {
160 HeapRegion* hr = iter.get_next();
161 // In set_containing_set() we check that we either set the value
162 // from NULL to non-NULL or vice versa to catch bugs. So, we have
163 // to NULL it first before setting it to the value.
164 hr->set_containing_set(NULL);
165 hr->set_containing_set(this);
166 }
167 #endif // ASSERT
168
169 if (_tail != NULL) {
170 assert(length() > 0 && _head != NULL, hrs_ext_msg(this, "invariant"));
171 _tail->set_next(from_list->_head);
172 } else {
173 assert(length() == 0 && _head == NULL, hrs_ext_msg(this, "invariant"));
174 _head = from_list->_head;
175 }
176 _tail = from_list->_tail;
177
178 _count.increment(from_list->length(), from_list->total_capacity_bytes());
179 from_list->clear();
180
181 verify_optional();
182 from_list->verify_optional();
183 }
184
185 void FreeRegionList::remove_all() {
186 check_mt_safety();
187 verify_optional();
188
189 HeapRegion* curr = _head;
190 while (curr != NULL) {
191 verify_region(curr);
192
193 HeapRegion* next = curr->next();
194 curr->set_next(NULL);
195 curr->set_containing_set(NULL);
196 curr = next;
197 }
198 clear();
199
200 verify_optional();
201 }
202
203 void FreeRegionList::remove_all_pending(uint target_count) {
204 check_mt_safety();
205 assert(target_count > 1, hrs_ext_msg(this, "pre-condition"));
206 assert(!is_empty(), hrs_ext_msg(this, "pre-condition"));
207
208 verify_optional();
209 DEBUG_ONLY(uint old_length = length();)
210
211 HeapRegion* curr = _head;
212 HeapRegion* prev = NULL;
213 uint count = 0;
214 while (curr != NULL) {
215 verify_region(curr);
216 HeapRegion* next = curr->next();
217
218 if (curr->pending_removal()) {
219 assert(count < target_count,
220 hrs_err_msg("[%s] should not come across more regions "
221 "pending for removal than target_count: %u",
222 name(), target_count));
223
224 if (prev == NULL) {
225 assert(_head == curr, hrs_ext_msg(this, "invariant"));
226 _head = next;
227 } else {
228 assert(_head != curr, hrs_ext_msg(this, "invariant"));
229 prev->set_next(next);
230 }
231 if (next == NULL) {
232 assert(_tail == curr, hrs_ext_msg(this, "invariant"));
233 _tail = prev;
234 } else {
235 assert(_tail != curr, hrs_ext_msg(this, "invariant"));
236 }
237
238 curr->set_next(NULL);
239 remove(curr);
240 curr->set_pending_removal(false);
241
242 count += 1;
243
244 // If we have come across the target number of regions we can
245 // just bail out. However, for debugging purposes, we can just
246 // carry on iterating to make sure there are not more regions
247 // tagged with pending removal.
248 DEBUG_ONLY(if (count == target_count) break;)
249 } else {
250 prev = curr;
251 }
252 curr = next;
253 }
254
255 assert(count == target_count,
256 hrs_err_msg("[%s] count: %u should be == target_count: %u",
257 name(), count, target_count));
258 assert(length() + target_count == old_length,
259 hrs_err_msg("[%s] new length should be consistent "
260 "new length: %u old length: %u target_count: %u",
261 name(), length(), old_length, target_count));
262
263 verify_optional();
264 }
265
266 void FreeRegionList::verify() {
267 // See comment in HeapRegionSetBase::verify() about MT safety and
268 // verification.
269 check_mt_safety();
270
271 // This will also do the basic verification too.
272 verify_start();
273
274 verify_list();
275
276 verify_end();
277 }
278
279 void FreeRegionList::clear() {
280 _count = HeapRegionSetCount();
281 _head = NULL;
282 _tail = NULL;
283 }
284
285 void FreeRegionList::print_on(outputStream* out, bool print_contents) {
286 HeapRegionSetBase::print_on(out, print_contents);
287 out->print_cr(" Linking");
288 out->print_cr(" head : "PTR_FORMAT, _head);
289 out->print_cr(" tail : "PTR_FORMAT, _tail);
290
291 if (print_contents) {
292 out->print_cr(" Contents");
293 FreeRegionListIterator iter(this);
294 while (iter.more_available()) {
295 HeapRegion* hr = iter.get_next();
296 hr->print_on(out);
297 }
298 }
299 }